Holes may be created in materials using a variety of techniques including, but not limited to, orbital drilling and reaming. Both orbital drilling and reaming have individual advantages when creating holes in multi-layered assemblies such as the fuselage of an aircraft. Reaming, for example, has been shown to induce beneficial stresses in the wall of a hole. These beneficial stresses result in improved fatigue life of the hole. However, the reaming process creates burrs in the area around the drilled hole. The process of removing these burrs requires the removal of the material layers from an assembly stack. This process is time consuming and labor intensive in large structures such as an aircraft fuselage.
In contrast, orbital drilling allows for the creation of holes without the need to remove material layers from an assembly stack. This method of manufacture is commonly known as one-up assembly. Orbital drilled holes, however, typically experience a fatigue knockdown when compared to reamed holes. Such a fatigue knockdown is due to a reaming process inducing beneficial residual stresses in the wall of the hole that improve fatigue life, whereas an orbital drilling process cuts cleanly and leaves the machined surface in a neutral state of stress. Further, conventional drilling processes are more time consuming and labor intensive. As such, methods and systems for orbital drilling that induces residual stresses in the wall of the hole may be desirable.